Github user myui commented on the issue:
https://github.com/apache/incubator-hivemall/pull/135
@maropu Could you check whether `to_json` and `from_json` works on Spark or
not if possible?
I'm not sure hcatalog is provided in Spark environment.
https://github.com/apache/incubator-hivemall/pull/135/commits/dd99307ef49f0507870573efdf5f2ae8da240cca#diff-357e4854869b2e21c38b1b437f11095aR56---
