CompactionQueryBuilder setIsDeleteDelta(boolean deleteDelta) {
    isDeleteDelta = deleteDelta;
    return this;
  }
If true, during CRUD minor compaction, Alter operations will result in the temp table's
partitions pointing to delete delta directories as opposed to insert deltas' directories (see
MinorQueryCompactor for details).
ql/src/java/org/apache/hadoop/hive/ql/txn/compactor/CompactionQueryBuilder.java