Flink Support is a HERE-proprietary implementation of using data from HERE platform catalogs and layers with Apache Flink framework. The distribution of processing jobs to workers is done by Flink but the data model is a HERE-proprietary format. There is no SQL-like interface, so you cannot select and filter data using Flink
In the end,
FlinkDataClient is a wrapper for regular
DataClient making sure that all asynchronous communication is syncronized to make it usable with Flink
Sink interfaces. There are no additional functions for tabular access.
HERE strongly suggests to use Flink Connector whenever possible as this allows to make use of the full power of Apache Flink framework.