This sounds like a bug.
What do you have after the union ?
Can you try to reproduce this with a script/data that you can share ?
If you can open a jira with details, that would be even better.
On 9/4/12 8:52 AM, Xavier Stevens wrote:
> I'm trying to do a UNION on two datasets with identical schemas
> (k:bytearray, v:chararray). When using the UNION operator like so:
> combined_data = UNION dataset1, dataset2;
> I get the following error:
> java.lang.RuntimeException: Unexpected data type java.util.ArrayList
> found in stream. Note only standard Pig type is supported when you
> output from UDF/LoadFunc
> Everything works fine if I store the two datasets separately without the
> This feels like a bug, but am I doing something wrong here?