This problem came from https://issues.cloudera.org/browse/IMPALA-1654 , CR at https://gerrit.cloudera.org/#/c/1563/ . This patch will make general predicates possible in most partition DDL operations. However, for NULL partitions, the old KV way no longer works. Broken cases are <string val>="" and <val>=null. This is due to the usage of HdfsPartitionPruner which is used for Query time partition pruning. Should we keep the old way of treating NULL partition as special cases?
Amos
