> addRow() is called in execute(). Does something look wrong with the call?
There is no need for an explicit flush, but addRow() is rather far below the layers of useful abstraction (and barely any seatbelts). Can you try logging the category/type fields of your inspector and make sure it is returning a Struct<> object inspector? HCat has a neater writer abstraction layer - https://github.com/apache/hive/blob/trunk/hcatalog/core/src/test/java/org/a pache/hive/hcatalog/data/TestReaderWriter.java#L141 That said, I¹m working on ORC WriterImpl today, so if this is simple enough to run/repro on a single VM, you can send me instructions about how to run this example & I can debug into it. Cheers, Gopal