Datasets store and retrieve data. Datasets are your means of reading from and writing to the CDAP’s storage capabilities. Instead of forcing you to manipulate data with low-level APIs, datasets provide higher-level abstractions and generic, reusable implementations of common data patterns.
Impersonation allows users to run programs and access datasets, streams, and other resources as pre-configured users (a principal). Currently, CDAP supports configuring impersonation at a namespace and at an application level, with application level configuration having a higher precedence than namespace level.
If impersonation is enabled, and you don't specify a principal for an application, stream,
or dataset, then the namespace owner's principal is used. If there is no namespace owner
or you are using the default namespace, then the default principal is used (as set by the
cdap.master.kerberos.principal in the
Details on the system configurations required are in the Administration Manual's section on Impersonation.