Hive and Impala are critical capabilities for your CDH cluster. Most often, everything you do inside your cluster has something to do with the data you're storing in HDFS; Hive and Impala dramatically simplify your interactions with said data.
Heimdali's first focus is creating a proper place for your data to live. Heimdali creates Hive databases and resource pools for your Impala queries to run in their dedicated space. All of these resources are created with security in mind and allows you to control who can interact with your data.