Viktor Khristenko created SPARK-20593:
-----------------------------------------

             Summary: Writing Parquet: Cannot build an empty group
                 Key: SPARK-20593
                 URL: https://issues.apache.org/jira/browse/SPARK-20593
             Project: Spark
          Issue Type: Question
          Components: Spark Core, Spark Shell
    Affects Versions: 2.1.1
         Environment: I use Apache Spark 2.1.1 (used 2.1.0 and it was the same, 
switched today). Tested only Mac
            Reporter: Viktor Khristenko
            Priority: Minor


Hi,

This is my first ticket and I apologize for/if I'm doing certain things in an 
improper way.

 I have a dataset:

root
|-- muons: array (nullable = true)
|    |-- element: struct (containsNull = true)
|    |    |-- reco::Candidate: struct (nullable = true)
|    |    |-- qx3_: integer (nullable = true)
|    |    |-- pt_: float (nullable = true)
|    |    |-- eta_: float (nullable = true)
|    |    |-- phi_: float (nullable = true)
|    |    |-- mass_: float (nullable = true)
|    |    |-- vertex_: struct (nullable = true)
|    |    |    |-- fCoordinates: struct (nullable = true)
|    |    |    |    |-- fX: float (nullable = true)
|    |    |    |    |-- fY: float (nullable = true)
|    |    |    |    |-- fZ: float (nullable = true)
|    |    |-- pdgId_: integer (nullable = true)
|    |    |-- status_: integer (nullable = true)
|    |    |-- cachePolarFixed_: struct (nullable = true)
|    |    |-- cacheCartesianFixed_: struct (nullable = true)

As you can see, there are 3 empty structs in this schema. I know 100% that I 
can read/manipulate/do whatever. However, when I try writing to disk in 
parquet, I get the following Exception:

ds.write.format("parquet").save(outputPathName):

java.lang.IllegalStateException: Cannot build an empty group
at org.apache.parquet.Preconditions.checkState(Preconditions.java:91)
at org.apache.parquet.schema.Types$BaseGroupBuilder.build(Types.java:622)
at org.apache.parquet.schema.Types$BaseGroupBuilder.build(Types.java:497)
at org.apache.parquet.schema.Types$Builder.named(Types.java:286)
at 
org.apache.spark.sql.execution.datasources.parquet.ParquetSchemaConverter.convertField(ParquetSchemaConverter.scala:535)
at 
org.apache.spark.sql.execution.datasources.parquet.ParquetSchemaConverter.convertField(ParquetSchemaConverter.scala:321)
at 
org.apache.spark.sql.execution.datasources.parquet.ParquetSchemaConverter$$anonfun$convertField$1.apply(ParquetSchemaConverter.scala:534)
at 
org.apache.spark.sql.execution.datasources.parquet.ParquetSchemaConverter$$anonfun$convertField$1.apply(ParquetSchemaConverter.scala:533)
So, basically I would like to understand if it's a bug or an intended 
behavior??? I also assume that it's related to the empty structs. Any help 
would be really appreciated!

I've quickly created stripped version and that one works without any issues!
For reference, I put a link to a original question on SO[1]

VK

[1] 
http://stackoverflow.com/questions/43767358/apache-spark-parquet-cannot-build-an-empty-group



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org

Reply via email to