CDAP-3051, we want to add an API to allow updating the properties of a dataset. That goes hand in hand with an API to retrieve the current properties. For example, if an app wants to add an index column to an index table, it first needs to know the existing set of index columns.
However, it is not trivial to retrieve the current properties of a dataset. The dataset service does not store the properties that were used to configure the dataset in its metadata. What is actually does is call the dataset definition's configure() method, and then stores the dataset spec returned from that. That spec has a properties field, but that does not necessarily reflect the properties that were passed in.
In order to reconfigure or to clone a dataset, the client needs to be able to retrieve the original properties with which the dataset was created. This Jira adds an API to do so.