NULL is a reserved word in C+. It doesn't work in C+ implementation.
It passed unittests
I changed only NULL value is involved with TajoDataType.Type.NULL to NULL_TYPE.
Thank you for your contribution!
I reviewed the patch. The patch looks good, and passes all unit tests
I've removed some unused imports.Then, I've committed the patch, fixing it as resolved.
SUCCESS: Integrated in Tajo-trunk-postcommit #571 (See https://builds.apache.org/job/Tajo-trunk-postcommit/571/)
TAJO-290: TajoDataType.Type.NULL should be NULL_TYPE. (DaeMyung Kang via jinho) (jinossy: https://git-wip-us.apache.org/repos/asf?p=incubator-tajo.git&a=commit&h=2e27a0232ac1bf48fe277a22a818d282866216c7)