When inserting empty data into a partitioned table, existing data would be removed. Tajo provides column value partition which is hive-style partition. In hive, when inserting empty data into a partition, there are two cases. If you use dynamic partitions, existing data never would be removed. But if you don't use dynamic partitions, existing data would be removed. When inserting a data to partition, tajo user don't specify each column and each column value. So, it is similar to dynamic partition of hive. It seems to update deletion logic of partitioned table.